In situ push-pull tests for the determination of TCE degradation and permanganate consumption rates

A simple, single-well push-pull test was conducted at a TCE-contaminated site to estimate the site-specific TCE degradation and permanganate (MnO ₄ ^- ) consumption rate. Known quantities of a conservative tracer (Br^-) and permanganate were rapidly injected into a saturated aquifer then periodically sampled during extraction from the same well. Concentrations of Br^-, TCE, and MnO ₄ ^- were measured; breakthrough curves (BTCs) for all species of solute were determined. Data analysis of BTCs for bromide and TCE showed that the first-order rate constant of TCE degradation by MnO ₄ ^- is 1.67 ± 0.152 h^-1. Further, the in situ MnO ₄ ^- demand rate by TCE and aquifer materials is estimated to be 0.54 ± 0.371 h ^-1. This study demonstrates that in situ push-pull tests are useful and economical tools for field investigations to determine contaminant reaction and oxidant consumption rates, which may then be used to optimize groundwater remediation designs.